Some solutions
If you miss the taste of old Cherrios, go to Trader Joe's and buy "Joe's O's"
If you miss the taste of old Fig Newtons, go to Aldi's and buy their knock-off version of them.
If you want really tasty soda pop, do what Laundress said, but you can also find great local sodas such as Foxon Park here in Connecticut (wonderful Birch Beer and the best Quinine Water I've found (yes, better than "Q")
If you want old Tide, Cheer and other, go to Latin American markets and buy their stuff. Not exactly the same, but close
If you miss old Dash, go to a British Goods market and buy low suds Ariel
If you miss old fresh Lamb, as I do, they way it was butchered in the Sixties, move to somewhere in the United Kingdom or Saudi Arabia.
Market analysts pay attention to your choices (when you actually HAVE a choice)